The association between gut microbiota and insomnia: A systematic review and meta-analysis.

BackgroundCystic Fibrosis (CF) is an autosomal recessive disease that affects the function of a number of organs, principally the lungs, but also the gastrointestinal tract. The manifestations of cystic fibrosis transmembrane conductance regulator (CFTR) dysfunction in the gastrointestinal tract, as well as frequent antibiotic exposure, undoubtedly disrupts the gut microbiota. To analyse the effects of CF and its management on the microbiome, we compared the gut microbiota of 43 individuals with CF during a period of stability, to that of 69 non-CF controls using 454-pyrosequencing of the 16S rRNA gene. The impact of clinical parameters, including antibiotic therapy, on the results was also assessed.ResultsThe CF-associated microbiome had reduced microbial diversity, an increase in Firmicutes and a reduction in Bacteroidetes compared to the non-CF controls. While the greatest number of differences in taxonomic abundances of the intestinal microbiota was observed between individuals with CF and the healthy controls, gut microbiota differences were also reported between people with CF when grouped by clinical parameters including % predicted FEV1 (measure of lung dysfunction) and the number of intravenous (IV) antibiotic courses in the previous 12 months. Notably, CF individuals presenting with severe lung dysfunction (% predicted FEV1 ≤ 40%) had significantly (p < 0.05) reduced gut microbiota diversity relative to those presenting with mild or moderate dysfunction. A significant negative correlation (−0.383, Simpson’s Diversity Index) was also observed between the number of IV antibiotic courses and gut microbiota diversity.ConclusionsThis is one of the largest single-centre studies on gut microbiota in stable adults with CF and demonstrates the significantly altered gut microbiota, including reduced microbial diversity seen in CF patients compared to healthy controls. The data show the impact that CF and it's management have on gut microbiota, presenting the opportunity to develop CF specific probiotics to minimise microbiota alterations.

BackgroundMicrobial dysbiosis has been linked to cystic fibrosis (CF); however, the composition of gut microbiota in adult CF patients in relation to severity of CF transmembrane conductance regulator (CFTR) gene mutation and nutritional status have not yet been explored. Study aimed to assess the gut microbiota composition in adults with CF, and its relationship with the severity of CFTR mutations, and BMI. MethodsGut microbiota of 41 adults with CF, and 26 non-CF controls were compared using whole 16S rRNA gene sequencing. Differences in the microbial community between groups of patients classified according to the severity of CFTR mutations, and BMI were assessed. The alpha diversity, beta diversity, and taxa abundance were identified to reflect gut microbiota composition. ResultsResults showed a significant decrease in alpha diversity of bacterial communities in CF compared to non-CF group, but no significant difference between the CF groups distinguished by the severity of CFTR mutations. However, more severe mutations were associated with the higher relative abundance of Bacteroides and Streptococcus and the lower relative abundance of Faecalibacterium and Blautia. Undernourished CF patients showed significantly lower alpha diversity compared to non-CF group and CF patients with BMI within the norm. Significant differences in the structure of the gut microbiota between CF and non-CF groups, as well as between BMI groups were also found. ConclusionsOur research indicates that CF is associated with alterations in gut microbiota in adults. Additionally, in adult CF patients, the composition of the gut microbiota is also related to BMI.

Background/Objectives: Diagnosing ASD in adults presents unique challenges, and there are currently no specific biomarkers for this condition. Most existing studies on the gut microbiota in ASD are conducted in children; however, the composition of the gut microbiota in children differs significantly from that of adults. This study aimed to study the gut microbiota of young adults with high-functioning ASD. Methods: Using metagenomic sequencing, we evaluated the gut microbiota in 45 adults with high-functioning ASD and 45 matched healthy controls. Results: Adjusting for sociodemographic information, dietary habits, and clinical data, we observed a distinct microbiota profile of adults with ASD in comparison to controls, with the intensity of autistic traits strongly correlating to microbial diversity (correlation coefficient = -0.351, p-value < 0.001). Despite a similar dietary pattern, the ASD group exhibited more gastrointestinal symptoms than the healthy controls. An internally validated machine-learning predictive model that combines the Autism Spectrum Quotient questionnaire score of individuals with their microbial features could achieve an area under the receiver operating characteristic curve (AUC) of 0.955 in diagnosing ASD in adults. Conclusions: This study evaluates the gut microbiota in adult ASD and highlights its potential as a non-invasive biomarker to enhance the diagnosis of ASD in this population group.

Independently, prebiotics and dietary protein have been shown to improve weight loss and/or alter appetite. Our objective was to determine the effect of combined prebiotic and whey protein on appetite, body composition and gut microbiota in adults with overweight/obesity. In a 12 week, placebo-controlled, double-blind study, 125 adults with overweight/obesity were randomly assigned to receive isocaloric snack bars of: (1) Control; (2) Inulin-type fructans (ITF); (3) Whey protein; (4) ITF+Whey protein. Appetite, body composition and gut microbiota composition/genetic potential were assessed. Compared to Control, body fat was significantly reduced in the Whey protein group at 12wks. Hunger, desire to eat and prospective food consumption were all lower with ITF, Whey protein and ITF+Whey protein compared to Control at 12 wks. Microbial community structure differed from 0 to 12 wks in the ITF and ITF +Whey Protein groups (i.e. increased Bifidobacterium) but not Whey Protein or Control. Changes in microbial genetic potential were seen between Control and ITF-containing treatments. Adding ITF, whey protein or both to snack bars improved several aspects of appetite control. Changes in gut microbiota may explain in part the effects of ITF but likely not whey protein.

1569 Background: Increasing evidence has shown that gut microbiota alterations may play a role in colorectal cancer risk. Diet, particularly fiber intake, may modify gut microbiota composition, which may consequently impact cancer risk development. We investigated the relationship between dietary fiber intake and gut microbiota in healthy humans. Methods: Using 16S rRNA gene sequencing, we assessed gut microbiota in fecal samples from 151 healthy adults in two independent study populations: Study A, n = 75 (healthy controls from a colorectal cancer case-control study), and Study B, n = 76 (polyp-free subjects from a cross-sectional colonoscopy study). We calculated energy-adjusted total dietary fiber intake of participants based on food frequency questionnaires. For each study population, we evaluated the relationship between quartiles of higher fiber intake as a continuous ordinal variable, and global gut microbiota community composition (via PERMANOVA of weighted UniFrac distance) and specific taxon abundance (via DESeq2). Results: We found that fiber intake was significantly associated with overall microbial community composition in Study B (p = 0.003) but not Study A (p = 0.68), after adjustment for age, sex, race, body mass index, and cigarette smoking. In a taxonomy-based meta-analysis of these two study populations, higher fiber intake was associated with lower abundance of genus Actinomyces (fold change [FC] = 0.769, p = 0.003), and higher abundance of genera Faecalibacterium (FC = 1.153, p = 0.03), Lachnospira (FC = 1.167, p = 0.04), and SMB53 (FC = 1.201, p = 0.05). A species-level meta-analysis showed an association between higher fiber intake and higher abundance of Faecalibacterium prausnitzii (FC = 1.165, p = 0.03) and lower abundance of Ruminococcus bromii (FC = 0.828, p = 0.08). Conclusions: Our results suggest that higher intake of dietary fiber may alter gut microbiota in healthy adults. Given the potentially modifiable nature of the gut microbiota through diet, these findings warrant further study of diet-microbiota based colorectal cancer prevention strategies.

The integrated dysbiosis of gut microbiota and altered host transcriptomics in irritable bowel syndrome (IBS) is yet to be known. This study investigated the associations among gut microbiota and host transcriptomics in young adults with IBS. Stool and peripheral blood samples from 20 IBS subjects and 21 healthy controls (HCs) collected at the baseline visit of an RCT were sequenced to depict the gut microbiota and transcriptomic profiles, respectively. The diversities, composition, and predicted metabolic pathways of gut microbiota significantly differed between IBS subjects and HCs. Nine genera were significantly abundant in IBS stool samples, including Akkermansia, Blautia, Coprococcus, Granulicatella, Holdemania, Oribacterium, Oscillospira, Parabacteroides, and Sutterella. There were 2264 DEGs found between IBS subjects and HCs; 768 were upregulated, and 1496 were downregulated in IBS participants compared with HCs. The enriched gene ontology included the immune system process and immune response. The pathway of antigen processing and presentation (hsa04612) in gut microbiota was also significantly different in the RNA-seq data. Akkermansia, Blautia, Holdemania, and Sutterella were significantly correlated with ANXA2P2 (upregulated, positive correlations), PCSK1N (downregulated, negative correlations), and GLTPD2 (downregulated, negative correlations). This study identified the dysregulated immune response and metabolism in IBS participants revealed by the altered gut microbiota and transcriptomic profiles.

Human sleep quality is intricately linked to gut health. Emerging research indicates that Bifidobacterium animalis subsp. lactis BLa80 has the potential to ameliorate gut microbiota dysbiosis. This randomized, placebo-controlled study evaluated the impact of BLa80 supplementation on sleep quality and gut microbiota in healthy individuals. One hundred and six participants were randomly assigned to receive either a placebo (maltodextrin) or BLa80 (maltodextrin + BLa80 at 10 billion CFU/day) for 8 weeks. Sleep quality was evaluated using the Pittsburgh Sleep Quality Index (PSQI), a validated tool consisting of 18 items assessing seven components of sleep quality over a one-month period, and the Insomnia Severity Index (ISI), a secondary measure of insomnia severity. Gut microbiota changes were assessed using 16S rRNA sequencing, while the in vitro gamma-aminobutyric acid (GABA) production capacity of BLa80 was analyzed by HPLC. After 8 weeks, the intervention group exhibited a significant reduction in the PSQI total score compared to the placebo group, suggesting improved sleep quality. While no significant changes in alpha diversity were noted, beta diversity differed markedly between groups. The gut microbiota predominantly consisted of Firmicutes, Bacteroidetes, Actinobacteria, Proteobacteria and Fusobacteria, collectively accounting for over 99.9% of the gut microbiota. Statistical analysis showed that BLa80 significantly decreased the relative abundance of Proteobacteria phylum and increased the abundance of Bacteroidetes, Fusicatenbacter, and Parabacteroides compared to placebo. PICRUSt2 analysis indicated noteworthy enhancements in the pathways of purine metabolism, glycolysis/gluconeogenesis, and arginine biosynthesis due to BLa80 intervention. Moreover, BLa80 demonstrated notable GABA production, potentially contributing to its effects on sleep quality modulation. These results demonstrate the ability of BLa80 to improve sleep quality through modulating gut microbiota and GABA synthesis, highlighting its potential as a beneficial probiotic strain.

IntroductionRecent studies suggest a link between gut microbiota and neurological diseases, implicating the microbiome’s role in neurological health. However, the specific alterations in the microbiome associated with migraine remain underexplored. This study aims to systematically review the existing literature to determine whether migraine patients are associated with changes in gut microbiota composition.MethodsA systematic review was conducted in accordance with the PRISMA statement. We included original empirical studies investigating the microbiome in migraine patients. Data extracted included study design, participant demographics, microbiome differences at various taxonomic levels, and measures of microbial diversity (alpha and beta diversity). The search and selection process involved four independent reviewers who assessed abstracts and full texts to ensure eligibility. The gut microbiota was evaluated using relative abundance and diversity indices.ResultsSix studies, encompassing various regions including China, Korea, and Italy, were included in the analysis. The results indicated significant differences in gut microbiota between migraine patients and controls. Key findings include a reduction in Faecalibacterium, a genus known for its anti-inflammatory properties, in migraine patients, including those with chronic migraine. Conversely, Veillonella exhibited elevated abundance compared to controls. Other taxa, such as Prevotella and Parabacteroides, showed variable associations with migraine across different studies, suggesting a dysbiotic gut environment in migraine patients.ConclusionThis review highlights that migraines are associated with specific alterations in gut microbiota, including decreased microbial diversity and changes in the abundance of key taxa. These findings suggest that gut microbiota dysbiosis may play a role in migraine pathophysiology. Further research is needed to explore the potential causal relationships and therapeutic implications, particularly targeting the microbiome in migraine management.Supplementary InformationThe online version contains supplementary material available at 10.1007/s13760-025-02779-y.

ABSTRACTThe role of the intestinal microbiota in coronavirus disease 2019 (COVID-19) is being elucidated. Here, we analyzed the temporal changes in microbiota composition and the correlation between inflammation biomarkers/cytokines and microbiota in hospitalized COVID-19 patients. We obtained stool specimens, blood samples, and patient records from 22 hospitalized COVID-19 patients and performed 16S rRNA metagenomic analysis of stool samples over the course of disease onset compared to 40 healthy individual stool samples. We analyzed the correlation between the changes in the gut microbiota and plasma proinflammatory cytokine levels. Immediately after admission, differences in the gut microbiota were observed between COVID-19 patients and healthy subjects, mainly including enrichment of the classes Bacilli and Coriobacteriia and decrease in abundance of the class Clostridia. The bacterial profile continued to change throughout the hospitalization, with a decrease in short-chain fatty acid-producing bacteria including Faecalibacterium and an increase in the facultatively anaerobic bacteria Escherichia-Shigella. A consistent increase in Eggerthella belonging to the class Coriobacteriia was observed. The abundance of the class Clostridia was inversely correlated with interferon-γ level and that of the phylum Actinobacteria, which was enriched in COVID-19, and was positively correlated with gp130/sIL-6Rb levels. Dysbiosis was continued even after 21 days from onset. The intestines tended to be an aerobic environment in hospitalized COVID-19 patients. Because the composition of the gut microbiota correlates with the levels of proinflammatory cytokines, this finding emphasizes the need to understand how pathology is related to the temporal changes in the specific gut microbiota observed in COVID-19 patients.IMPORTANCE There is growing evidence that the commensal microbiota of the gastrointestinal and respiratory tracts regulates local and systemic inflammation (gut-lung axis). COVID-19 is primarily a respiratory disease, but the involvement of microbiota changes in the pathogenesis of this disease remains unclear. The composition of the gut microbiota of patients with COVID-19 changed over time during hospitalization, and the intestines tended to be an aerobic environment in hospitalized COVID-19 patients. These changes in gut microbiota may induce increased intestinal permeability, called leaky gut, allowing bacteria and toxins to enter the circulatory system and further aggravate the systemic inflammatory response. Since gut microbiota composition correlates with levels of proinflammatory cytokines, this finding highlights the need to understand how pathology relates to the gut environment, including the temporal changes in specific gut microbiota observed in COVID-19 patients.

PurposeClinical studies focusing on the association between the gut microbiota and obstructive sleep apnea (OSA) are limited. This study aimed to explore the relationship between intermittent hypoxia and the composition of gut microbiota in adults by analyzing the differences in the characteristics and functional distribution of gut microbiota between patients with different severities of OSA and healthy individuals.Patients and MethodsA cohort of 113 individuals from the First Affiliated Hospital of Sun Yat-sen University underwent overnight polysomnography from July 2019 to August 2021. The individuals included 16 healthy controls and 97 patients with OSA, categorized by the apnea-hypopnea index into mild, moderate, and severe groups. Fecal samples were analyzed using high-throughput sequencing of the 16S rRNA V3–V4 region to assess gut microbiota composition and function. Correlation analysis was used to evaluate the association between clinical indicators and microbiota markers.ResultsIn patients with OSA, the gut microbiota diversity and the abundance of specific microbes that produce short-chain fatty acids decreased (P<0.05). The phyla Verrucomicrobia and Candidatus Saccharibacteria, genera Gemmiger and Faecalibacterium, and the species Gemmiger formicilis exhibited decreasing abundance with increasing OSA severity. Correlation analysis revealed a robust association between the proportion of total sleep time, characterized by nighttime blood oxygen saturation below 90%, and the alterations in the gut microbiota, demonstrating that elevated levels of desaturation are correlated with pronounced microbiota dysbiosis (P<0.05).ConclusionCompared to the control group, the intermittent hypoxia exhibited by patients with OSA may be related to alterations in the composition and structure of the gut microbiota. Our results demonstrate the importance of monitoring hypoxia indicators in future clinical practice.

BackgroundSkin lesions can occur during the progression of pancreatic cancer. With growing attention on the gut-skin axis, these lesions may be linked to the microbiota. Microbiota play a crucial role in skin-related conditions, including hair loss and overall skin health. However, few studies have investigated the dynamic changes in gut and skin microbiota associated with skin lesions during cancer progression. In this study, 16S rRNA gene sequencing was used to investigate the dynamic changes of the gut microbiota in mice without non-depilation (Unepi) and depilation (Epi) after PAN02 cell injection. We also revealed the changes in skin microbiota of Unepi mice (Unepi_D) and Epi mice (Epi_D) after depilation.ResultsOur study found that the alpha diversity significantly increased in Unepi_D, indicating an imbalance in gut microbiota homeostasis. In the skin microbiota, certain genera such as Staphylococcus and Devosia were up-regulated, while others like Lactobacillus were down-regulated. Similarly, in the gut microbiota, Parasutterella was enriched, whereas Blautia showed reduced abundance. In the Epi group, the trend of increasing pathogenic bacteria and decreasing probiotics suggests a disrupted microbial environment that may contribute to skin injury through the gut–skin axis. These findings highlight potential microbial targets for diagnosis and therapeutic intervention in pancreatic cancer-associated skin complications.ConclusionTherefore, our findings provide new insights and references for the prevention and treatment of skin-related diseases in clinical practice. Specific gut and skin microbiota alterations may serve as potential biomarkers or therapeutic targets for managing skin complications in pancreatic cancer patients.Clinical trial numberNot applicable.

Introduction: Chronic heart failure (HF) is linked to elevated serum TNF-α levels and affects multiple signaling pathways in non-cardiomyocytes, such as immune cells, intestinal epithelial cells, lymphatic endothelial cells, vascular cells, and their interactions. The combined dysbiosis of host transcriptomics and gut microbiota concerning altered TNF-α signaling in older adults with HF remains unknown. Methods: We recruited 10 older adults with heart failure (HF) (6 females) and 16 healthy controls (HCs) (10 females) from the Northeastern U.S. Non-fasting peripheral blood and stool samples were collected. Serum TNF-α was assayed using Enzyme-linked Immunosorbent Assay (ELISA) kits. Differentially expressed genes (DEGs) between HF and HCs were investigated using the R package "DESeq2" after aligning the raw blood RNA sequence data to the reference database and undergoing quality control. The QIAGEN Ingenuity Pathway Analysis (IPA) was used to analyze the canonical pathways associated with the DEGs. The 16S rRNA V4 gene regions of stool samples were sequenced and processed using the Mothur 1.42.3 pipeline. The Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) was used to predict the metagenomic functions of different gut microbiota compositions. Results: The mean ages of the HF and HC subjects were 73.50 (SD = 8.33) and 63.19 (SD = 7.75), respectively. HF subjects had significantly higher serum TNF-α levels than HCs (p &lt; 0.05). Among the DEGs, HF subjects had 18 downregulated genes (e.g., AK5, FAM167A, RGCC, and SARDH) and 3 upregulated genes (SMPD3, TMIGD3, and FRRS1) compared with HCs. TNF signaling (p &lt; 0.01) was one of the significantly different canonical pathways in the DEGs between HF and HCs. HF subjects had significantly enriched Mogibacterium and diminished Sutterella than HCs (p &lt; 0.05) and lower P53 signaling pathway activity than HCs (p &lt; 0.05) among the predicted functions in stool samples. Conclusions: By analyzing serum TNF-α, whole transcriptomics, and gut microbiota, we identified higher serum TNF-α, differentially expressed genes (DEGs) and their canonical pathways, and distinct compositions and predicted functions of gut microbiota in older adults with HF compared to healthy controls. These findings suggest that TNF-α signaling may be a potential target for developing precise HF interventions and highlight the need for further large-scale multi-omics analysis in understanding and treating HF.

Antibiotics are widely used to treat bacterial infection and reduce the mortality rate, while antibiotic overuse can cause gut microbiota dysbiosis. The impact of antibiotics on gut microbiota is not fully understood. In our study, four commonly used antibiotics (ceftazidime, cefoperazone-sulbactam, imipenem-cilastatin, and moxifloxacin) were given subcutaneously to mice, and their impacts on the gut microbiota composition and serum cytokine levels were evaluated through 16S rRNA analysis and a multiplex immunoassay. Antibiotic treatment markedly reduced gut microbiota diversity and changed gut microbiota composition. Antibiotic treatment significantly increased and decreased the abundance of Firmicutes and Bacteroidota, respectively. The antibiotic treatments increased the abundance of opportunistic pathogens such as Enterococcus and decreased that of Lachnospiraceae and Muribaculaceae. For moxifloxacin, the significantly high abundance of Enterococcus and Klebsiella was observed after 14 and 21 days of treatment. However, a relatively low abundance of opportunistic pathogens was found after 14 days of imipenem-cilastatin treatment. Additionally, the serum levels of various pro-inflammatory cytokines, such as IL-1β, IL-12 (p70), and IL-17, significantly increased after 21 days of antibiotic treatments. Overall, these results provide a guide for rational use of antibiotics in clinical settings: short-term use of moxifloxacin is recommended with regard to gut microbiota health, and the 14-day use of imipenem-cilastatin may have a less severe impact than other antibiotics.IMPORTANCEAntibiotic treatments are directly associated with changes in gut microbiota and are effective against both pathogens and beneficial bacteria. Gut microbiota dysbiosis induced by antibiotic treatment could increase the risk of some diseases. Therefore, an adequate understanding of gut microbiota changes after antibiotic use is crucial. In this study, we investigated the effects of continuous treatment with antibiotics on gut microbiota, serum cytokines, and intestinal inflammatory response. Our results suggest that short-term use of moxifloxacin is recommended, and the 14-day use of imipenem-cilastatin may have a less severe effect on gut microbiota health than cefoperazone-sulbactam. These results provide useful guidance on the rational use of antibiotics with regard to gut microbiota health.

ObjectiveThe aim of this study is to investigate the changes in gut microbiota before and after Helicobacter pylori (Hp) eradication, assess the structural distribution of gut colonies in individuals infected with Hp, and examine the alterations in gut microbiota following Hp eradication.MethodsPatients diagnosed with Hp infection between June 1, 2021, and December 31, 2021, were included in the study. A total of 26 patients who underwent standard quadruple first-line therapy for Hp eradication were prospectively enrolled. Fecal samples were collected 1 day before treatment and 6 weeks after treatment. The gut microbiota was sequenced using the 16S rRNA next-generation gene sequencer to assess changes in microbiota composition ratios and diversity, before and after treatment.ResultsAmong the 26 patients with Hp infection, aged between 19 and 55 years, 18 had positive results in the 13C urea breath test, while 8 were diagnosed through gastroscopic histopathological examination. Changes in gut microbiota diversity were observed before and after Hp eradication. At 56 days post-treatment, alpha diversity changes were not significant, whereas beta diversity changes differed in the gut microbiota. Variations were also noted in the relative abundance and composition ratios of the gut microbiota at the phylum and genus levels before and after Hp eradication. Compared to the pre-eradication state, the metabolic pathways of the gut microbiota were less abundant following Hp eradication.ConclusionSignificant changes were observed in the beta diversity of the gut microbiota, the relative abundance at the phylum and genus levels, and metabolic pathways within a short period following Hp eradication.

Introduction: Antibiotic treatments cause changes in gut microbiota. Dysbiosis of gut microbiota has been linked to metabolic diseases such as type 2 diabetes mellitus (T2DM). Objective: To evaluate whether changes in gut microbiota due to antibiotic treatment in patients colonized by H. pylori, could be related to improvements in carbohydrate metabolism. Material and Method: A prospective case-control study were performed. Clinical data, carbohydrate metabolism, and microbiota composition in feces (determined by 16S rRNA gene (V3-V4) sequencing using the Illumina Miseq) before and 2 months after eradication treatment were analyzed. Results: We studied 40 cases and 20 controls (60% women, respectively). Average age was 47.0 ± 2 vs. 43.6 ± 2.7 years old. 70% vs. 60% had family history of digestive disorders and 42.5% vs. 40% clinical history of gastrointestinal disease. After antibiotics, we found significant changes in gut microbiota profile at phylum, family, genus and species levels. The Chao and Shannon indices showed a decreased in bacterial richness and diversity in patients (pre and post H. pylori eradication) compared to controls. We observed an improvement in glucose homeostasis in cases 2 month after H. pylori eradication treatment, with decrease in HbA1c (p=0.014), 60’ (p=0.018) and 120’ (p=0.019) glucose post OGTT. Changes in Rikenellaceae, Butyricimonas, E. biforme, B. fragilis, and Megamonas were inversely associated with changes in glucose level and Hb1Ac in patients which got H. pylori eradication. Conclusion: H. pylori eradication treatment causes alteration in human gut microbiota. The glucose homeostasis improvement found after antibiotic treatment was related to changes in microbial community, particularly in Megamonas and Butyricimonas genus, Rikenellaceae family and E. biforme and B. fragilis species. SCFA-producing and glucose remover bacterias could play an important role in these associations. Disclosure I. Cornejo-Pareja: None. G. Martin-Nuñez: None. M. Roca-Rodriguez: None. I. Moreno-Indias: None. L. Vinuela: None. L. Coin-Arangüez: None. I. Mancha-Doblas: None. F. Tinahones: None.